The study proposed in this project will compare the effects of alcohol and alcohol expectancy on risk-taking in men and women. Increased risk-taking has been implicated in a large percentage of alcohol-related traffic fatalities. However, efforts to characterize alcohol's effects on the probability and magnitude of risk-taking behavior have produced inconclusive results. Moreover, research has shown that the expectation of alcohol's effects, apart from the pharmacological actions of ethanol, can affect behavior. The proposed study will measure risk-taking maneuvers in a driving simulator. This paradigm places explicit contingencies for success (bonuses) or failure (penalties) on driving performance. The novelty of our paradigm is our definition of risk. We have defined risk as the possibility of incurring loss. We are able to modify the level of risk by altering the penalty within the task. Our preliminary data demonstrate that manipulation of penalty modifies driving behavior. Specifically, subjects undertake fewer risk-taking maneuvers in high penalty situations than in low penalty situations. Using this paradigm in conjunction with an extended balanced placebo design, we will assess the separate and combined effects of alcohol and the expectation of alcohol. Our paradigm will provide a valuable resource for increasing the public's awareness of the dangers of driving while under the influence of alcohol.